Universal Access To All Knowledge
Home Donate | Store | Blog | FAQ | Jobs | Volunteer Positions | Contact | Bios | Forums | Projects | Terms, Privacy, & Copyright
Search: Advanced Search
Anonymous User (login or join us)
Upload
Search Results
Results: 1 through 50 of 3,593 (1.176 secs)
You searched for: subject:"ecology"
[1] 2 3 4 5 6 7 8 9 10 11     Next    Last
[texts]huang tu di qu zao lin jing yan - song chao shu

Keywords: ecology
Downloads: 139
[texts]The Effectiveness of China’s National Forest Protection Program and National-level Nature Reserves, 2000 to 2010 - Guopeng Ren
There is profound interest in knowing the degree to which Chinas institutions are capable of protecting its natural forests and biodiversity in the face of economic and political change. Chinas two most important forest protection policies are its National Forest Protection Program (NFPP) and its National-level Nature Reserves (NNRs). The NFPP was implemented in 17 provinces starting in the year 2000 in response to deforestation-caused flooding...
Keywords: Ecology
[texts]Mechanism of β-Aminobutyric Acid-Induced Resistance in Wheat to the Grain Aphid, Sitobion avenae - He-He Cao
The non-protein amino acid β-aminobutyric acid (BABA) could induce plant resistance to a broad spectrum of biotic and abiotic stresses. However, BABA-induced plant resistance to insects is less well-studied, especially its underlying mechanism. In this research, we applied BABA to wheat seedlings and tested its effects on Sitobion avenae. When applied as a soil drench, BABA significantly reduced weight of S...
Keywords: Ecology
[texts]Extracting robust trends in species' distributions from unstructured opportunistic data: a comparison of methods - Nick JB Isaac
1. Policy-makers increasingly demand robust measures of biodiversity change over short time periods. Long-term monitoring schemes provide high-quality data, often on an annual basis, but are taxonomically and geographically restricted. By contrast, opportunistic biological records are relatively unstructured but vast in quantity. Recently, these data have been applied to increasingly elaborate science and policy questions, using a range of methods...
Keywords: Ecology
[texts]The impacts of historical barriers on floristic patterns of plant groups with different dispersal abilities in the Ryukyu Archipelago, Japan - Koh Nakamura
The effects of historical barriers in biogeographical patterns are expected to persist differently depending on dispersal abilities of organisms. We tested two hypotheses that plant groups with different dispersal abilities display different floristic patterns, and that historical barriers can explain floristic differentiation patterns in plants with low dispersal ability but not in plants with higher dispersal ability, in the seed plant flora of the Ryukyu Archipelago...
Keywords: Ecology
[texts]Spatial distribution and seasonal fluctuations of Drosophila on Santa Catalina Island with an emphasis on the repleta species group - Joyce Y Kao
Santa Catalina Island is a small island off the coast of southern California and for its modest size harbors several species of flies from the Drosophila genus. We performed an island-wide survey of Drosophila species to ascertain which species were endemic to the island and where they were most abundant. In doing so, we have assembled useful sampling information for researchers who wish to conduct field studies on Santa Catalina Island...
Keywords: Ecology
[texts]Seasonality dynamics of avian influenza occurrences in Central and West Africa - Trevon Fuller
Understanding seasonal cycles of viruses originating in wildlife can provide insight into their likelihood of persistence in animal populations and inform policies to limit spillover to human populations. Avian influenza virus (AIV) is an important zoonotic agent causing seasonal occurrence of avian influenza (AI) in wild birds in temperate areas. Although the seasonality of AIV transmission in tropical birds is largely unknown, peaks of influenza activity in human populations in the tropics coi...
Keywords: Ecology
[texts]An appraisal of the classic forest succession paradigm with the shade tolerance index - Jean F Lienard
In this paper we revisit the classic theory of forest succession that relates shade tolerance and species replacement and assess its validity to understand patch-mosaic patterns of forested ecosystems of the USA. We introduce a macroscopic parameter called the "shade tolerance index" and compare it to the classic continuum index in southern Wisconsin forests. We exemplify shade tolerance driven succession in White Pine--Eastern Hemlock forests using computer simulations and analyzing approximate...
Keywords: Ecology
[texts]Data-intensive multidimensional modeling of forest dynamics - Jean F Lienard
Forest dynamics are highly dimensional phenomena that are poorly understood theoretically. Modeling these dynamics is data-intensive and requires repeated measurements taken with a consistent methodology. Forest inventory datasets offer unprecedented opportunities to model these dynamics, but they are analytically challenging due to high dimensionality and sampling irregularities across years. We develop a methodology for predicting forest stand dynamics using such datasets...
Keywords: Ecology
[texts]Spatial variation in water loss predicts terrestrial salamander distribution and population dynamics - William Peterman
Many patterns observed in ecology, such as species richness, life history variation, habitat use, and distribution have physiological underpinnings For many ectothermic organisms temperature relations shape these patterns, but for terrestrial amphibians, water balance may supersede temperature as the most critical physiologically-limiting factor. Many amphibian species have little resistance to water loss, which restricts them to moist microhabitats and may significantly affect foraging, dispers...
Keywords: Ecology
[texts]Pushed beyond the brink: Allee effects, environmental stochasticity, and extinction - Gregory Roth
To understand the interplay between environmental stochasticity and Allee effects, we analyze persistence, asymptotic extinction, and conditional persistence for stochastic difference equations. Our analysis reveals that persistence requires that the geometric mean of fitness at low densities is greater than one. When this geometric mean is less than one, asymptotic extinction occurs with high probability for low initial population densities...
Keywords: Ecology
[texts]Elements of ecology - Clarke, George L. (George Leonard), 1905-
Includes bibliography
Keywords: Ecology
Downloads: 1,488
[texts]Climate change triggers morphological and life-history evolution in response to predators - Edmund Hart
Although climate change is expected to reorganize entire communities, this restructuring might reflect either direct ecological or evolutionary responses to abiotic conditions or indirect effects mediated through altered species interactions. We tested the hypothesis that changes in trophic interaction strength due to altered predator abundance have a cascading evolutionary response in a prey species (Daphnia pulex)...
Keywords: Ecology
Downloads: 1
[audio]07.12.2007 lisovskiy na radio svobodniy golos - yuriy shevchuk
07.12.2007
Keywords: ecology
Downloads: 24
[texts]shan xi sheng shui tu bao chi jing yan jie shao 陕西省水土保持经验介绍 (Volume 2) - shan xi sheng shui li ting 陕西省水利厅

Keywords: ecology
Downloads: 147
[texts]kun chong tu pu (Volume 1) - wang yun wu zhou jian ren

Keywords: ecology
Downloads: 147
[texts]lin xue gai lun (Volume 6) - cai yi chun zhang hua ling (yi)

Keywords: ecology
Downloads: 175
[texts]ji lin sheng zhong yao shou ce - ji lin sheng wei sheng ting

Keywords: ecology
Downloads: 230
[texts]Linking indices for biodiversity monitoring to extinction risk theory - Michael A. McCarthy
Biodiversity indices often combine data from different species when used in monitoring programs. Heuristic properties can suggest preferred indices, but we lack objective ways to discriminate between indices with similar heuristics. Biodiversity indices can be evaluated by determining how well they reflect management objectives that a monitoring program aims to support. For example, the Convention on Biological Diversity requires reporting about extinction rates, so simple indices that reflect e...
Keywords: Ecology
[texts]The dark side of theoretical ecology - Lev V. Kalmykov
Good science must be clearly transparent in its theories, models and experiments. Earlier David Tilman drew attention to the fact that ecologists investigate interspecific competition phenomenologically, rather than mechanistically. To create a mechanistic model of a complex dynamic system we need to logically describe interactions of its subsystems which lead to emergence of new properties on the macro-level...
Keywords: Ecology
Downloads: 1
[texts]lin ye ji kan (Volume 1) - zhong guo ke xue yuan lin ye tu rang yan jiu suo

Keywords: ecology
Downloads: 185
[texts]jiang xi zhong yao (Volume 1) - jiang xi sheng zhong yao yan jiu suo

Keywords: ecology
Downloads: 265
[texts]jiang xi nong ye bing chong hai zhi bing hai bu fen - jiang xi sheng nong ye ting zhi bao zhi jian chu jiang xi nong xue yuan kun chong bing li jiao yan zu

Keywords: ecology
Downloads: 309
[texts]A solution to the biodiversity paradox by logical deterministic cellular automata - Lev V. Kalmykov
The paradox of biological diversity is the key problem of theoretical ecology. The paradox consists in the contradiction between the competitive exclusion principle and the observed biodiversity. This principle was formulated incorrectly because of limitations of the traditional black-box models of interspecific competition. The principle is very important as the basis for understanding evolutionary processes...
Keywords: Ecology
[texts]A novel inference of the fundamental biodiversity number for multiple immigration-limited communities - Champak Beeravolu Reddy
Neutral community theory postulates a fundamental quantity, θ, which reflects the species diversity on a regional scale. While the recent genealogical formulation of community dynamics has considerably enhanced quantitative neutral ecology, its inferential aspects have remained computationally prohibitive. Here, we make use of a generalized version of the original two-level hierarchical framework in order to define a novel estimator for θ, which proves to be computationally efficient and robus...
Keywords: Ecology
Downloads: 2
[texts]lin xue gai lun (Volume 2) - cai yi chun wu bao qun (yi)

Keywords: ecology
Downloads: 155
[texts]mian hua ji qi zai pei - chen busheng yang huisheng

Keywords: ecology
Downloads: 254
[texts]Nutritional aspects of honey bee-collected pollen and constraints on colony development in the eastern Mediterranean - Dorit Avni
Pollen is the main protein and lipid source for honey bees (Apis mellifera), and nutritionally impoverished landscapes pose a threat to colony development. To determine colony nutritional demands, we analyzed a yearly cycle of bee-collected pollen from colonies in the field and compared it to colony worker production and honey bee body composition, for the first time in social insects. We monitored monthly bee production in ten colonies at each of seven sites throughout Israel, and trapped polle...
Keywords: Ecology
Downloads: 3
[texts]Allee effects are necessary to explain the emergence of ‘elastic’ ranges - Alexander Kubisch
In times of severe environmental changes and resulting shifts in the geographical distribution of animal and plant species it is crucial to unravel the mechanisms responsible for the dynamics of species’ ranges. Without such a mechanistic understanding reliable projections of future species distributions are difficult to derive. Species ranges may be highly dynamic and subject to ‘elastic’ behavior, i.e...
Keywords: Ecology
Downloads: 1
[texts]The web of life : a first book of ecology - Storer, John H. (John Humphries), b. 1888
"A Mentor book."
Keywords: Ecology
Downloads: 174
[texts]lin ye ming ci - zhong guo ke xue yuan bian yi ju

Keywords: ecology
Downloads: 278
[texts]huang hai chao jian dai sheng tai xue yan jiu (Volume 1(2)) - gu li ya nuo wa

Keywords: ecology
Downloads: 172
[texts]lin xue gai lun (Volume 1) - cai yi chun wu bao qun

Keywords: ecology
Downloads: 154
[texts]jie kang xing fang xian jun de fen lei wen ti - dai guan qun yuan yong sheng (yi)

Keywords: ecology
Downloads: 189
[texts]jiang su nong zuo wu pin zhong zhi di yi fen ce shui dao (Volume 1) - jiang xi sheng nong ye ting zhong zi chu

Keywords: ecology
Downloads: 356
[texts]Emergence of structural and dynamical properties of ecological mutualistic networks - Samir Suweis
Mutualistic networks are formed when the interactions between two classes of species are mutually beneficial. They are important examples of cooperation shaped by evolution. Mutualism between animals and plants has a key role in the organization of ecological communities. Such networks in ecology have generally evolved a nested architecture independent of species composition and latitude; specialist species, with only few mutualistic links, tend to interact with a proper subset of the many mutua...
Keywords: Ecology
Downloads: 3
[texts]On a solution of the biodiversity paradox and a competitive coexistence principle - Lev V. Kalmykov
The biodiversity paradox is the central problem in theoretical ecology. The paradox consists in the contradiction between the competitive exclusion principle and the observed biodiversity. This contradiction is the key subject of the long-standing and continuing biodiversity debates. The paradox impedes our insights into biodiversity conservation. Previously we proved that due to a soliton-like behaviour of population waves complete competitors can indefinitely coexist in one closed homogeneous ...
Keywords: Ecology
Downloads: 2
[texts]Black rhinoceros demography should be stage, not age, based. - Peter R Law
Biologically meaningful and standardized definitions of life stages are essential for demographic studies, especially for endangered and intensively managed species such as rhinoceros. Focusing on the black rhinoceros Diceros bicornis, we argue that standardized biological definitions of calf, subadult, and adult, rather than age classes, provide the appropriate basis for black rhinoceros demography...
Keywords: Ecology
Downloads: 1
[texts]kun chong tu pu (Volume 2) - wang yun wu zhou jian ren

Keywords: ecology
Downloads: 163
[texts]ma lei zuo wu - yang hui sheng

Keywords: ecology
Downloads: 285
[texts]Early warning signs in social-ecological networks - Samir Suweis
A number of social-ecological systems exhibit complex behaviour associated with nonlinearities, bifurcations, and interaction with stochastic drivers. These systems are often prone to abrupt and unexpected instabilities and state shifts that emerge as a discontinuous response to gradual changes in environmental drivers. Predicting such behaviours is crucial to the prevention of or preparation for unwanted regime shifts...
Keywords: Ecology
Downloads: 2
[texts]lin xue gai lun (Volume 5) - zhang hua ling wu bao qun (yi)

Keywords: ecology
Downloads: 219
[texts]Response to climate change is related to species traits in the Lagomorpha - Katie Leach
Climate change during the last five decades has impacted on natural systems significantly and the rate of current climate change is of great concern among conservation biologists. Here, we assess the projected change in the bioclimatic envelopes of all 87 species in the mammalian order Lagomorpha under future climate using expertly validated species distribution models. Results suggest that climate change will impact more than two-thirds of Lagomorphs, with leporids (rabbits, hares and jackrabbi...
Keywords: Ecology
Downloads: 1
[texts]Assessing the Use of Antiviral Treatment to Control Influenza - Sarah C Kramer
Vaccines are the cornerstone of influenza control policy, but can suffer from several drawbacks. Seasonal influenza vaccines are prone to production problems and low efficacies, while pandemic vaccines are unlikely to be available in time to slow a rapidly spreading global outbreak. Antiviral therapy was found to be beneficial during the influenza A(H1N1)pdm09 pandemic even with limited use; however, antiviral use has decreased further since then...
Keywords: Ecology
Downloads: 3
[texts]Meteorological conditions influence short-term survival and dispersal in a reinforced long-lived bird population. - Loïc A Hardouin
1. A high immediate mortality rate of released animals is an important cause of translocation failure (release cost). Post-release dispersal (i.e. the movements from the release site to the first breeding site) has recently been identified as another source of local translocation failure. In spite of their potential effects on conservation program outcomes, little is known about the quantitative effects of these two sources of translocation failure and their interactions with environmental facto...
Keywords: Ecology
Downloads: 2
[texts]Sampling principles for biodiversity study - Xubin Pan
Sampling is a fundamental tool in ecology and critical for biodiversity measurement. However, basic principles of biodiversity sampling have been overlooked for many years. In this paper, I proposed and explored five principles of sampling for a specific area and biodiversity study. The first principle of sampling, species increasing with area, is that the number of species increases with the area...
Keywords: Ecology
Downloads: 1
[texts]ji nan di li - shan dong shi fan xue yuan di li xi

Keywords: ecology
Downloads: 178
[texts]Sap flow through petioles and petioles reveals leaf-level responses to light and vapor pressure deficit in the tropical tree Tabebuia rosea (Bignoniaceae) - Adam Roddy
Continuous measurements of sap flow have been widely used to measure water flux through tree stems and branches. However, these measurements lack the resolution necessary for determining fine-scale, leaf-level responses to environmental variables. We used the heat ratio method to measure sap flow rates through leaf petioles and leaflet petiolules of saplings of the tropical tree Tabebuia rosea (Bignoniaceae) to determine how leaf and leaflet sap flow responds to variation in light and vapor pres...
Keywords: Ecology
[texts]Numerous new mitogenomic sequences and multiple new environmental DNA markers for invasive bighead and silver carp (Hypophthalmichthys nobilis and H. molitrix) populations in North America - Richard F. Lance
Invasive Asian bighead and silver carp (Hypophthalmichthys nobilis and H. molitrix) pose a substantial threat to North American waterways. Recently, environmental DNA (eDNA), the use of species-specific genetic assays to detect the DNA of a particular species in a water sample, has gained recognition as a tool for tracking the invasion front of these species toward the Great Lakes. The goal of this study was to develop new species-specific conventional PCR (cPCR) and quantitative (qPCR) markers ...
Keywords: Ecology
Downloads: 2
[texts]Mapping migration in a songbird using high-resolution genetic markers - Kristen C Ruegg
Neotropical migratory birds are declining across the Western Hemisphere, but conservation efforts have been hampered by the inability to assess where migrants are most limited–the breeding grounds, migratory stopover sites, or wintering areas. A major challenge has been the lack of an efficient, reliable, and broadly applicable method for connecting populations across the annual cycle. Here we show how high-resolution genetic markers can be used to identify populations of a migratory bird, the...
Keywords: Ecology
Downloads: 1
[1] 2 3 4 5 6 7 8 9 10 11     Next    Last
Advanced search

Group results by:

> Relevance
Mediatype
Collection

Related mediatypes

texts
audio